Red Cabbage Indicator

Discussion:
The red cabbage indicator can tell you what the pH levels of a substance when compared to the indicator chart. In comparison to the universal indicator, the cabbage indicator can be slightly inaccurate. The pH levels were more recognisable when using the Universal indicator which resulted in more accurate answers.

The pH of the common household substances did have a few recognisable patterns. Almost all of the substances ranged from pH levels of 4-8, with only 2 with high acid levels. We tested lemon juice which had a pH level of 2, making it a strong acid. I expect that most other food items would have a higher pH level to avoid damage to the mouth and throat during/after consumption. Lemon juice contains citric and ascorbic acid (vitamin c)

along with limes, oranges and grapefruit.

Lemon and limes are the most acidic whilst the rest stand as weak acids. The cleaning products tended to have a similar pH level, ranging from a pH level of 5-8. The were in the mid range in terms of strength/weakness, because different cleaning products are used to clean different things. Cleaning product with a pH level above 7 are considered Alkaline products and are better at cleaning dirt, grease, oils and other organic items. Cleaning products with a pH level below 7 are considered acidic products and are better at cleaning calcium, rust and other mineral non-organic items. For both the personal care items (Shampoo and conditioner) the pH level was 4-5, they are generally more on the acidic side of the pH scale because they assist in preserving the hairs own natural acidity. They keep the hairs cuticle layers oriented downward to improve and shine and appearance of hair. You see pH in everyday life in the foods you

eat such as lemons (pH 2) or even bread (pH of 5-6). You can also see it in soil as the plant growth and survival is impacted on the acidity of the soil, in personal care products like shampoo and soap and in pools where the pH level is closely observed as a high or low pH level can affect swimmers and promote the growth of algae.

In order to improve the accuracy of this practical we could use pipette pumps to ensure that our 1mL amounts are accurate. This will result in the levels of solution in each test tube being the same.

We could extend this prac by researching the types of acids each household item contained to assist in the comparison of products.

Conclusion:

Overall the serial dilution of the practical was quite inaccurate, despite this, the testing of the household items with the universal indicator was accurate. The universal indicator was more accurate than the cabbage indicator, but inaccuracy in the measurements altered the results.